• Too much reach and not enough frequency.
  Effective web advertising ensures that a good percentage of the target audience see the advert a suitable number of times.
• Selling the features rather than the benefits of what is being offered.
• Too much copy. Over cluttering adverts will dilute the main message.
• Not emphasizing the unique selling points.
• Using an image which does not clearly show explain the product / service.
• Giving up on advertising before it has had a chance to work. Avoid the quest for instant gratification.
• Changing your web advertising copy too frequently.
• Choosing the wrong media. What media works for one business may not work for others.
• The business owner does not always know best. Too much product knowledge does not allow the product to be viewed afresh.
• Too much priority on selective targeting. High coverage and frequency yield the best results for your web advertising campaign.

These are all factors to why adverts fail.